Skip to content
Tax CalculatorUK
Calculate

Capital Gains Tax Calculator

Capital gains are taxed at 18% within your unused basic rate band and 24% above it, for shares and residential property alike. The first £3,000 of gains each year is tax-free.

Tax year 2026/27 · Estimates, not personal tax advice

£

Sale price minus purchase price and allowable costs

£
£

Salary, profit and other income before allowances

Capital Gains Tax

£3,463.80

on a taxable gain of £17,000
Annual exempt amount£3,000.00
Gain taxed at 18%£10,270.00
Gain taxed at 24%£6,730.00
CGT due£3,463.80

Uses general CGT rates, not Business Asset Disposal Relief or Investors' Relief. UK residential property gains with tax due normally have a 60-day reporting and payment deadline; residency can change reporting obligations.

Rates and rules used

Tax year 2026/27

Default year 2026/27 (6 April to 5 April). 2025/26 and 2024/25 figures are kept for comparison where the calculator offers a year choice.

Independent site, not affiliated with HMRC. Always check GOV.UK for the latest figures.

How this calculation works

  1. 01Subtract losses from gains.
  2. 02Deduct the £3,000 annual exempt amount.
  3. 03Work out how much basic rate band your income leaves.
  4. 04Tax gains in that space at 18% and the rest at 24%.

Real payroll can differ because tax and NI are worked out per pay period, and your tax code may include adjustments HMRC hasn't told you about. See our methodology.

Reporting deadlines

Gains on UK residential property must be reported and paid within 60 days of completion. Other gains go on your Self Assessment return. Business Asset Disposal Relief rates differ and aren't covered here.

Understanding your capital gains tax calculator result

Capital Gains Tax applies to the gain, not the full sale proceeds. The calculator deducts allowable purchase and sale costs and the available annual exempt amount before using the income information to allocate rates.

Estimating a share disposal

Scenario: Enter sale proceeds, original cost and dealing fees, then add taxable income for the year. Include only assets outside tax-sheltered accounts.

How to use the result: The result estimates tax on the net gain. If several disposals or losses exist, combine them under the matching and loss-relief rules before relying on the figure.

Details to check before relying on the estimate

  • Exclude assets held in an ISA or pension.
  • Past capital losses may reduce the taxable gain.
  • Residential property can have a shorter reporting and payment deadline.

Putting the estimate into perspective

Keep a record of the disposal and the costs used in this estimate. If you have multiple transactions, do not assume adding isolated results reproduces the treatment of the combined gains and losses.

Frequently asked questions

Is there CGT on my main home?

Usually not, thanks to Private Residence Relief, provided it's been your only or main home throughout and the grounds aren't excessive.

Check it on GOV.UK: Capital Gains Tax rates (opens GOV.UK in a new tab)

How is a capital gain calculated?

The gain is the sale price minus what you paid and certain allowable costs. The annual exempt amount is then deducted and the rest is taxed at the rate that applies to your income and asset type.

Check it on GOV.UK: Capital Gains Tax allowances (opens GOV.UK in a new tab)

Do I have to report a gain to HMRC?

It depends on the asset and amount. Property disposals have their own reporting deadline, and other gains may be reported through Self Assessment. Check GOV.UK for the current rules.

Check it on GOV.UK: Self Assessment tax returns (opens GOV.UK in a new tab)

Related calculators

Related guides

  • Capital Gains Tax Explained — How Capital Gains Tax works in 2026/27, the £3,000 allowance, 18% and 24% rates, and when you need to report.
  • UK Tax-Free Allowances — A summary of UK tax-free allowances for 2026/27: Personal Allowance, savings, dividends, CGT, trading, property, ISAs and pensions.